/Engine/Source/Editor/UnrealEd/Classes/Editor/EditorEngine.h
Launch on callbacks
void HandleStageStarted ( const [FString](API\Runtime\Core\Containers\FString) & InStage, [TWeakPtr](API\Runtime\Core\Templates\TWeakPtr)< [SNotificationItem](API\Runtime\Slate\Widgets\Notifications\SNotificationItem) > NotificationItemPtr )